Method and apparatus for investigating pipes with ultrasonic phased array sensors

Inspecting pipe wall of pipeline for defects involves controlling a portion of virtual sensors to irradiate ultrasound signals into the pipe wall at irradiation angle(s) which is inclined to a normal to the pipe wall, receiving ultrasound signals reflected by bordering surfaces of the pipe wall in the virtual sensors, and evaluating the received signals from differing bordering surfaces. Inspecting pipe wall of pipeline for defects involves: (a) introducing measuring sensors into the pipeline, each measuring sensor (16) comprising an array of controllable sensor elements; (b) defining virtual sensors, each virtual sensors comprising an array of neighboring sensor elements; (c) controlling at least a portion of the virtual sensors to irradiate ultrasound signals into the pipe wall at irradiation angle(s) which is inclined to a normal to the pipe wall; (d) receiving ultrasound signals reflected by bordering surfaces of the pipe wall in at least a portion of the virtual sensors; and (e) evaluating the received signals from differing bordering surfaces to determine pipe wall defects. An Independent claim is also included for a device for inspecting the pipe wall of a pipeline for defects.